Do vortex generators really work.

[Old Koreelah]

Theres a D10 on my current work site but try as much as they can it just won't lift off with or without flap (maybe the problem is the scraper in front that it's pushing?)Sorry been a long day

Agreed, Paul. The D-9 that was working in the bush when I was a young bloke had an atrocious power-to-weight ratio.

 

 

[Oscar]

Theres a D10 on my current work site but try as much as they can it just won't lift off with or without flap (maybe the problem is the scraper in front that it's pushing?)Sorry been a long day

I believe Liebherr make a suitable set for a D10-so good you can get VTOL!

 

 

[paulh]

Seriously though, threads like this are one of the reasons why I read this forum - interesting topic, good technical information, people helping each other etc.

 

Regarding the superstol type of aircraft, in my very limited experience I would think that these aircraft are highly optimised for a small aspect of the flight envelope and flying on the back end of the power/drag curve at low level seems like not a good place for the average weekend warrior. No doubt lots of fun but the risk seems high flying close to the edge without lots of training, practice and currency

 

 

[Dafydd Llewellyn]

Seriously though, threads like this are one of the reasons why I read this forum - interesting topic, good technical information, people helping each other etc.Regarding the superstol type of aircraft, in my very limited experience I would think that these aircraft are highly optimised for a small aspect of the flight envelope and flying on the back end of the power/drag curve at low level seems like not a good place for the average weekend warrior. No doubt lots of fun but the risk seems high flying close to the edge without lots of training, practice and currency

I tend to class it with tractor-pulling and such things.

 

 

[Head in the clouds]

Regarding the superstol type of aircraft, in my very limited experience I would think that these aircraft are highly optimised for a small aspect of the flight envelope and flying on the back end of the power/drag curve at low level seems like not a good place for the average weekend warrior. No doubt lots of fun but the risk seems high flying close to the edge without lots of training, practice and currency

STOL operations certainly aren't for everyone but for some people they make the difference between being able to do the job with an aeroplane, or needing a helicopter. On a station wherever a plane can replace a helicopter a lot of cost can be saved. In some cases the station may be able to do without a helicopter altogether*, hiring one when essential for mustering, in other cases where a plane can do the job it frees up the helicopter for other work. *Stations that don't have extensive areas of rugged terrain or tall timber.

 

We need to keep in mind that for some people flying isn't all about going quickly from place to place. Bush aerial work often involves quite the opposite in fact, loitering around in the air as slowly as possible to move stock or as an eye-in-the-sky directing ground operations. Hence the existence of the two quite unrelated endorsements of 'Aerial Spotting' and 'Mustering'.

 

If it were sufficiently rugged a plane like the Seeker could probably gain a lot more sales in the bush if it was also capable of SuperSTOL type of landings because these days that is very much on the bush-pilot shopping list. The days of stations having multiple aircraft, one for each type of operation, are gone. Many stations don't have can't afford any aircraft at all anymore and many others have to make do with one where they previously had more. So a major consideration when buying is not just "can I see the hole in the fence", "can I see the bogged cow", "can I see the empty water trough", but "can I get on the ground, fix the problem and get airborne again?" Spotting any of the aforementioned, or a thousand-and-one other matters typical of any day on the land, and not being able to do anything about it without flying half-an-hour each way to the homestead to fetch the helicopter just isn't an option in the current financially strained environment.

 

It's not just the cost of the aircraft but also the wasted time now that stations can afford fewer staff than ever before. As an example of that, the first station I worked on had accommodation for over fifty stockmen, a boreman, mechanic, gardener, saddlemaker, two fencers, grader operator, and married quarters for a cook and up to six managers. A total staff of over seventy, and the kitchens to cater for them. Today that same station carries the same number of cattle (40-55,000 according to season) but has one Manager, a cook, a head stockman, four jackeroos/jillaroos, one man who does the combined job of boreman and mechanic, a pilot and a couple of unpaid backpackers - just eleven people. Fencing, saddlery, grading and major mill, bore, generator or pump repairs now have to be outsourced as finances allow.

 

The SuperSTOL landing does, as someone mentioned earlier, require a rather more sophisticated landing gear and a strong rear fuselage to absorb the shocks from banging the the tailwheel on first and the resultant thump onto the mains but contrary to what might be expected it doesn't take a great deal of skill and, in a plane designed for the purpose, is as safe as any other landing. It does take a bit of practice of course but those who do it regularly aren't possessed with any special abilities.

 

Certainly, at some point during the approach, you do have to commit to the landing as you are intentionally going to put the aircraft behind the power/drag curve but that does have its advantages too. It allows for great accuracy, very low ground speed and a short roll-out. If the aircraft is properly designed so that the gear can handle it and it won't drop a wing during the procedure then it is a perfectly safe manoeuvre. And - it's not that different from many similar operations performed in a helicopter.

 

Confined area operations, as they're called, require you to get the helicopter into a spot which isn't possible in a 'conventional' approach to the hover, usually due to tall obstacles. If the small space happens to be close to rising ground requiring a downwind approach, for example, then you have two options, you can deliberately go behind the 'dead man's curve' - a speed/height situation where you can't autorotate if the engine quits - or you can perform a near-autorotational circling approach timed to a 'zero/zero' - zero groundspeed/zero height - right on the spot. The latter is similar to the SuperSTOL landing because there's no go-around if you get it wrong but with a little practice it's way safer than spending a fair while in the dead man's region while hover-descending into your own wash and risking another deadly helicopter syndrome called vortex ring if you try to hurry it, not to mention 'loss of tailrotor effectiveness' if the tailwind is in the wrong quarter.

 

So - the SuperSTOL landing is far from being intended as a crowd-pleasing circus trick or the aerial equivalent of tractor-pulling. It's actually the future of standard operations in the bush and a good step forward in aircraft design for forgiving handling at high alpha and well developed shock-absorbing landing gear systems. Note that the Highlander SuperSTOL has a long-travel gas-strut on the tailwheel and on the main gear there are monoshock struts that cost $5K - but there are cheaper ways as shown by the Storch and the Wilga, to name just two.

 

No doubt the predicted objection will be - "it's all very well being able to land short but then you can't take-off again". That's not so true as it might appear - in the early 1990s I was one of two pilots on a well-known Kimberley station which had an R22 helicopter and a Super Cub and I had another R22 and sometimes a Drifter was also available. We could often save the helicopters for mustering and use the Cub for most of the mechanical work because with a bit of acquired technique you could do a remarkably short landing. I frequently landed in the yards if the cattle were out of them and there was no space outside to land, but more usually you might have to land in a short space that was clear but among rocks or scrub. I always carried a machete or two and then it was just a matter of clearing some rocks and cutting some scrub and you had enough room to take-off. And a helicopter can get out of anywhere it can land because you have the benefit of ground-effect when conducting a 'max-performance take-off'.

 

 

[facthunter]

The fact still remains that hitting something when you are almost stopped is a lot better than hitting something when you are almost flying. The take-of is more demanding of good assessment. Nev

 

 

[Dafydd Llewellyn]

STOL operations certainly aren't for everyone but for some people they make the difference between being able to do the job with an aeroplane, or needing a helicopter. On a station wherever a plane can replace a helicopter a lot of cost can be saved. In some cases the station may be able to do without a helicopter altogether*, hiring one when essential for mustering, in other cases where a plane can do the job it frees up the helicopter for other work. *Stations that don't have extensive areas of rugged terrain or tall timber.We need to keep in mind that for some people flying isn't all about going quickly from place to place. Bush aerial work often involves quite the opposite in fact, loitering around in the air as slowly as possible to move stock or as an eye-in-the-sky directing ground operations. Hence the existence of the two quite unrelated endorsements of 'Aerial Spotting' and 'Mustering'.

 

If it were sufficiently rugged a plane like the Seeker could probably gain a lot more sales in the bush if it was also capable of SuperSTOL type of landings because these days that is very much on the bush-pilot shopping list. The days of stations having multiple aircraft, one for each type of operation, are gone. Many stations don't have can't afford any aircraft at all anymore and many others have to make do with one where they previously had more. So a major consideration when buying is not just "can I see the hole in the fence", "can I see the bogged cow", "can I see the empty water trough", but "can I get on the ground, fix the problem and get airborne again?" Spotting any of the aforementioned, or a thousand-and-one other matters typical of any day on the land, and not being able to do anything about it without flying half-an-hour each way to the homestead to fetch the helicopter just isn't an option in the current financially strained environment.

 

It's not just the cost of the aircraft but also the wasted time now that stations can afford fewer staff than ever before. As an example of that, the first station I worked on had accommodation for over fifty stockmen, a boreman, mechanic, gardener, saddlemaker, two fencers, grader operator, and married quarters for a cook and up to six managers. A total staff of over seventy, and the kitchens to cater for them. Today that same station carries the same number of cattle (40-55,000 according to season) but has one Manager, a cook, a head stockman, four jackeroos/jillaroos, one man who does the combined job of boreman and mechanic, a pilot and a couple of unpaid backpackers - just eleven people. Fencing, saddlery, grading and major mill, bore, generator or pump repairs now have to be outsourced as finances allow.

 

The SuperSTOL landing does, as someone mentioned earlier, require a rather more sophisticated landing gear and a strong rear fuselage to absorb the shocks from banging the the tailwheel on first and the resultant thump onto the mains but contrary to what might be expected it doesn't take a great deal of skill and, in a plane designed for the purpose, is as safe as any other landing. It does take a bit of practice of course but those who do it regularly aren't possessed with any special abilities.

 

Certainly, at some point during the approach, you do have to commit to the landing as you are intentionally going to put the aircraft behind the power/drag curve but that does have its advantages too. It allows for great accuracy, very low ground speed and a short roll-out. If the aircraft is properly designed so that the gear can handle it and it won't drop a wing during the procedure then it is a perfectly safe manoeuvre. And - it's not that different from many similar operations performed in a helicopter.

 

Confined area operations, as they're called, require you to get the helicopter into a spot which isn't possible in a 'conventional' approach to the hover, usually due to tall obstacles. If the small space happens to be close to rising ground requiring a downwind approach, for example, then you have two options, you can deliberately go behind the 'dead man's curve' - a speed/height situation where you can't autorotate if the engine quits - or you can perform a near-autorotational circling approach timed to a 'zero/zero' - zero groundspeed/zero height - right on the spot. The latter is similar to the SuperSTOL landing because there's no go-around if you get it wrong but with a little practice it's way safer than spending a fair while in the dead man's region while hover-descending into your own wash and risking another deadly helicopter syndrome called vortex ring if you try to hurry it, not to mention 'loss of tailrotor effectiveness' if the tailwind is in the wrong quarter.

 

So - the SuperSTOL landing is far from being intended as a crowd-pleasing circus trick or the aerial equivalent of tractor-pulling. It's actually the future of standard operations in the bush and a good step forward in aircraft design for forgiving handling at high alpha and well developed shock-absorbing landing gear systems. Note that the Highlander SuperSTOL has a long-travel gas-strut on the tailwheel and on the main gear there are monoshock struts that cost $5K - but there are cheaper ways as shown by the Storch and the Wilga, to name just two.

 

No doubt the predicted objection will be - "it's all very well being able to land short but then you can't take-off again". That's not so true as it might appear - in the early 1990s I was one of two pilots on a well-known Kimberley station which had an R22 helicopter and a Super Cub and I had another R22 and sometimes a Drifter was also available. We could often save the helicopters for mustering and use the Cub for most of the mechanical work because with a bit of acquired technique you could do a remarkably short landing. I frequently landed in the yards if the cattle were out of them and there was no space outside to land, but more usually you might have to land in a short space that was clear but among rocks or scrub. I always carried a machete or two and then it was just a matter of clearing some rocks and cutting some scrub and you had enough room to take-off. And a helicopter can get out of anywhere it can land because you have the benefit of ground-effect when conducting a 'max-performance take-off'.

Well, you are talking about a rather specialised tool; in effect a flying Jeep. I've done a couple hundred hours in Super Cubs, glider towing - including outlanding retrieves - and yes, you can do very short landings in them, by the old bush pilot's trick of dumping the flaps at the appropriate moment. I've seen Jim Hazelton land an Auster on Nestor Slepcev's strip that he used for his Storch demonstrations - two up - AND take off again, very nearly as short as Nestor.

And no, the Seeker is NOT STOL. Its particular strengths are its ability to give the pilot a gentle ride in low-level turbulence that would rattle your teeth in a Cessna 172, and its safe manoeuvrability and good field of view - plus the ability to carry remote sensing gear that's normally only suitable for a helicopter. And it has the structural integrity to have a long fatigue life under that usage. That's not the job you describe.

 

What you are talking about is a commercial operation as defined by CAR 206 - and as such, does not belong on a recreational flying forum.

 

I'd imaging the Wilga would be just about ideal for what you are describing - if it had a sensible price and a longer fatigue life. That's if a fixed-wing device is appropriate for this at all; a jump-start gyroplane would really fit the bill.

 

However, Nev is correct, I think - what you need is a short take-off aircraft with what I would describe as a "Blue-bush" undercarriage. How long do tundra tyres last on rough ground? I suspect a long-travel Wilga-style undercarriage with 800 x 6 tyres might be more practical. A wheel-ski type setup would give considerable protection against rabbit holes.

 

However, the obvious question is, how large is the market? Certificating a niche-market aircraft is very risky. There have been many attempts at what you describe in the past; the most commercially-successful was probably the Pilatus Porter. You have only to look at the market penetration of jump-start gyroplanes to see how great the risk is.

 

 

[facthunter]

If you want to apply a practicability and needed test It would be a small market. The first thing you need is an undercarriage that actually has energy absorbing legs. If you have too much travel it ,means the plane is too high when not compressed. The BIG tyres are a Canada playing around thing and don't really fit with any concept of thinking about drag. Great to go to fishing spots where no roads exist.

 

The Pilatus Porter is a good workhorse

 

STOL means low speed flight at BOTH critical stages. Gusts of wind will make this somewhat risky at times. I would rather have something with a bit more controllability (penetration) which can be put down exactly where I want it to and won't be blown around in like a paper bag in a school playground.. This needs wing loading to be a bit higher than most STOL machines especially the simpler ones. That we can afford and use under RAAus Rules. Complex ones use a bit of extra power to overcome the penalties of lift devices, with their inferior lift/drag characteristics.. I'm not such a fan of really low speed flight as I once was. One of the main advantages of an aircraft is it's ability to go places, quickly. This would need a design that has a high figure for cruise speed over stall speed. That's a fairly complex thing to achieve when high altitude comes into it, but that's outside of our operations. Nev

 

 

[Head in the clouds]

I'm afraid both of you are assuming rather a lot, quite obviously not having spent any meaningful time out on the stations.

 

Well, you are talking about a rather specialised tool; in effect a flying Jeep....

Specialised yes, but not a flying Jeep at all, there are no major payloads to carry nor any particularly rough treatment handed out to the airframe. All that's needed is the ability to get one person and a few tools or two persons into and out of locations that don't have ready made airstrips. Most of the country is quite landable as long as you have agile rudder control to dodge a few rocks or scrub and can pull up quite short.

 

And no, the Seeker is NOT STOL. Its particular strengths are its ability to give the pilot a gentle ride in low-level turbulence that would rattle your teeth in a Cessna 172, and its safe manoeuvrability and good field of view - plus the ability to carry remote sensing gear that's normally only suitable for a helicopter. And it has the structural integrity to have a long fatigue life under that usage. That's not the job you describe.

I wasn't meaning to talk about the Seeker and STOL in the same sentence, I was just referring to its enviably good visibility, which, like the Drifter's, is a great advantage when stooging around looking for sneaky bullocks or Mickeys hiding in the scrub.

 

What you are talking about is a commercial operation as defined by CAR 206 - and as such, does not belong on a recreational flying forum.

Things may have changed so maybe it's time I applied for another determination from CASA. However, last time I went through all this it was determined that when the plane is owned by the station, being operated on the station, and no-one is being paid as a pilot then it was a private operation regardless of what the person flying it was doing, whether flying the bore run, delivering smoko to the yards, mustering, spotting, culling, taking the cook to the pub, you name it. If you are mustering or spotting you need to have a mustering or spotting endorsement and have completed low-level training, but not necessarily a Commercial licence ...

 

As I mentioned in the previous post I had my own helicopters on various stations, and my own AOC, and when I used my own machines it was a Commercial operation and I billed the station for provision of aerial work services. When I flew their helicopters or planes I did so as an employed stockman and the flying was a private operation. Since I was the Chief Pilot of my operation and at times had up to 13 employed pilots and five helicopters you can imagine that CASA was very much aware of how our operations were conducted and we were audited 3-4 times a year and they never had a problem with our mix of private and commercial ops. Their determination was very simple - if you hire yourself out as a pilot it must be a commercial operation under an AOC/Ops Manual/CP but if part of your duties as a stockman involved your flying a station aircraft it could be done on a private licence/operation just the same as driving the station's trucks on a private licence. In fact I don't know of any stations at all that ever had an AOC/CP for their mustering operations unless they also supplied a mustering service to neighbouring stations like John Weymouth's Helimuster from Victoria River Downs, Slingsby's Heliwork from Kununurra, North Australian Helicopters from Katherine and/or smaller operations like my own which operated from satellite bases.

 

So, as I said maybe with the recent CAR re-organisation it may have changed, although I doubt it, and I will request a new determination because this matter keeps on getting raised, BUT whatever their answer it's not going to stop or affect private landowners buying a plane and using it on their station. And whatever they use it for, even if they stick to whatever the new rules might (or might not) be, those private owners flying happily around their station looking at their cows (if you will), will still need benefit from having the type of bushplane I was discussing, so, as long you don't mind, I will keep discussing it on the Recflying forum ...

 

I'd imaging the Wilga would be just about ideal for what you are describing - if it had a sensible price and a longer fatigue life. That's if a fixed-wing device is appropriate for this at all; a jump-start gyroplane would really fit the bill.

The Wilga's good but too thirsty, and general servicing/maintenance is too costly, for stations at present. What stations need is a cheap utility, as I mentioned it doesn't have to carry much at all, the Wilga is overkill. No, a gyroplane wouldn't fit the bill at all, a Cartercopter system would perform well (if Carter were selling) but think farmers here ...! A few gyro people have taken their machines out bush in the past and used them to muster and they work fine but you'd not get many station cockies to buy one.

 

..... I think - what you need is a short take-off aircraft with what I would describe as a "Blue-bush" undercarriage. How long do tundra tyres last on rough ground? I suspect a long-travel Wilga-style undercarriage with 800 x 6 tyres might be more practical.

I don't know what you mean by blue-bush gear. There's no need for tundra tyres, just reasonably large diameter with long-travel suspension. The suspension travel is to absorb the 'smack-down' landing not because of rough ground though you might choose to land on blacksoil clumpy grasslands if you had the long suspension travel and that wouldn't hurt tundra tyres anyway.

 

A wheel-ski type setup would give considerable protection against rabbit holes.

I've never seen a rabbit or a rabbit hole on a cattle station. Now - if you had something as protection against anthills ...?

 

However, the obvious question is, how large is the market? Certificating a niche-market aircraft is very risky. There have been many attempts at what you describe in the past; the most commercially-successful was probably the Pilatus Porter....

A large enough market, and no need for certification. Anything bigger than an LSA is going to be too expensive anyway. Pilatus Porter size is ridiculous, even in the hey-day of Australian cattle stations they rarely had planes that big/expensive. The Stationair was reputedly called that because marketers thought it was the ideal size for station owners going to town to do the shopping. A lamentable lack of market research went into that decision because when they go shopping they don't fly they take the station trucks to carry back the tonnes of goods that every station needs. A very few Stationair sized planes did end up out there predominantly used by owners who have two or three stations spread a fair distance apart, and for attending the markets. Otherwise the rare larger planes out there were mainly DC3 size or larger, flying frozen beef overseas.

 

The first thing you need is an undercarriage that actually has energy absorbing legs. If you have too much travel it ,means the plane is too high when not compressed.

There's no need for the legs to be at full extension when the aircraft weight is on them, their compressing - and remaining compressed - during the landing phase absorbs energy and reduces the angle of attack hence preventing bouncing.

 

STOL means low speed flight at BOTH critical stages. Gusts of wind will make this somewhat risky at times. I would rather have something with a bit more controllability (penetration) which can be put down exactly where I want it to and won't be blown around in like a paper bag in a school playground

At most times during the working part of the year (dry season/winter) the weather is perfect for flying.

 

.

 

 

[Dafydd Llewellyn]

I'm afraid both of you are assuming rather a lot, quite obviously not having spent any meaningful time out on the stations.

 

Specialised yes, but not a flying Jeep at all, there are no major payloads to carry nor any particularly rough treatment handed out to the airframe. All that's needed is the ability to get one person and a few tools or two persons into and out of locations that don't have ready made airstrips. Most of the country is quite landable as long as you have agile rudder control to dodge a few rocks or scrub and can pull up quite short.

 

I wasn't meaning to talk about the Seeker and STOL in the same sentence, I was just referring to its enviably good visibility, which, like the Drifter's, is a great advantage when stooging around looking for sneaky bullocks or Mickeys hiding in the scrub.

 

Things may have changed so maybe it's time I applied for another determination from CASA. However, last time I went through all this it was determined that when the plane is owned by the station, being operated on the station, and no-one is being paid as a pilot then it was a private operation regardless of what the person flying it was doing, whether flying the bore run, delivering smoko to the yards, mustering, spotting, culling, taking the cook to the pub, you name it. If you are mustering or spotting you need to have a mustering or spotting endorsement and have completed low-level training, but not necessarily a Commercial licence ...

 

As I mentioned in the previous post I had my own helicopters on various stations, and my own AOC, and when I used my own machines it was a Commercial operation and I billed the station for provision of aerial work services. When I flew their helicopters or planes I did so as an employed stockman and the flying was a private operation. Since I was the Chief Pilot of my operation and at times had up to 13 employed pilots and five helicopters you can imagine that CASA was very much aware of how our operations were conducted and we were audited 3-4 times a year and they never had a problem with our mix of private and commercial ops. Their determination was very simple - if you hire yourself out as a pilot it must be a commercial operation under an AOC/Ops Manual/CP but if part of your duties as a stockman involved your flying a station aircraft it could be done on a private licence/operation just the same as driving the station's trucks on a private licence. In fact I don't know of any stations at all that ever had an AOC/CP for their mustering operations unless they also supplied a mustering service to neighbouring stations like John Weymouth's Helimuster from Victoria River Downs, Slingsby's Heliwork from Kununurra, North Australian Helicopters from Katherine and/or smaller operations like my own which operated from satellite bases.

 

So, as I said maybe with the recent CAR re-organisation it may have changed, although I doubt it, and I will request a new determination because this matter keeps on getting raised, BUT whatever their answer it's not going to stop or affect private landowners buying a plane and using it on their station. And whatever they use it for, even if they stick to whatever the new rules might (or might not) be, those private owners flying happily around their station looking at their cows (if you will), will still need benefit from having the type of bushplane I was discussing, so, as long you don't mind, I will keep discussing it on the Recflying forum ...

 

The Wilga's good but too thirsty, and general servicing/maintenance is too costly, for stations at present. What stations need is a cheap utility, as I mentioned it doesn't have to carry much at all, the Wilga is overkill. No, a gyroplane wouldn't fit the bill at all, a Cartercopter system would perform well (if Carter were selling) but think farmers here ...! A few gyro people have taken their machines out bush in the past and used them to muster and they work fine but you'd not get many station cockies to buy one.

 

I don't know what you mean by blue-bush gear. There's no need for tundra tyres, just reasonably large diameter with long-travel suspension. The suspension travel is to absorb the 'smack-down' landing not because of rough ground though you might choose to land on blacksoil clumpy grasslands if you had the long suspension travel and that wouldn't hurt tundra tyres anyway.

 

I've never seen a rabbit or a rabbit hole on a cattle station. Now - if you had something as protection against anthills ...?

 

A large enough market, and no need for certification. Anything bigger than an LSA is going to be too expensive anyway. Pilatus Porter size is ridiculous, even in the hey-day of Australian cattle stations they rarely had planes that big/expensive. The Stationair was reputedly called that because marketers thought it was the ideal size for station owners going to town to do the shopping. A lamentable lack of market research went into that decision because when they go shopping they don't fly they take the station trucks to carry back the tonnes of goods that every station needs. A very few Stationair sized planes did end up out there predominantly used by owners who have two or three stations spread a fair distance apart, and for attending the markets. Otherwise the rare larger planes out there were mainly DC3 size or larger, flying frozen beef overseas.

 

There's no need for the legs to be at full extension when the aircraft weight is on them, their compressing - and remaining compressed - during the landing phase absorbs energy and reduces the angle of attack hence preventing bouncing.

 

At most times during the working part of the year (dry season/winter) the weather is perfect for flying.

 

.

Ta - that's useful info. And you're right, I've not had the opportunity to spend time out on the stations, so that makes your input doubly useful.

So - a trailing-link suspension a la Wilga but with more travel; and using oleos that sit about 80% closed under static load, and 800 x 6 tyres; and a REAL stall speed around 42 knots CAS, with handling characteristics allowing you to be at maybe 48 CAS on short finals; and two seats in tandem, so the front one is ahead of the wing; and LSA type cost. A tractor tailwheel layout for good propeller clearance. And no carpets.

 

With a pannier suitable for carrying tools etc.?

 

 

[Head in the clouds]

So - a trailing-link suspension a la Wilga but with more travel; and using oleos that sit about 80% closed under static load, and 800 x 6 tyres; and a REAL stall speed around 42 knots CAS, with handling characteristics allowing you to be at maybe 48 CAS on short finals; and two seats in tandem, so the front one is ahead of the wing; and LSA type cost. A tractor tailwheel layout for good propeller clearance. And no carpets.

With a pannier suitable for carrying tools etc.?

Now you're cooking on gas ... well, pretty close to what I'm thinking about anyway.

 

What's a blue-bush landing gear?

 

 

[metalman]

Ta - that's useful info. And you're right, I've not had the opportunity to spend time out on the stations, so that makes your input doubly useful.So - a trailing-link suspension a la Wilga but with more travel; and using oleos that sit about 80% closed under static load, and 800 x 6 tyres; and a REAL stall speed around 42 knots CAS, with handling characteristics allowing you to be at maybe 48 CAS on short finals; and two seats in tandem, so the front one is ahead of the wing; and LSA type cost. A tractor tailwheel layout for good propeller clearance. And no carpets.

 

With a pannier suitable for carrying tools etc.?

Sound remarkably similar to a PA18, I've been pondering what I'd like in an aircraft, and as I've already got all the plans from piper for a supercub I'll be heading down that way, although with a few changes , the main one being widening the fuse for side by side seating ( I know a pa20 does that ,but it's certified ,and the cub does fly slower) , a 100 knot cruise is fine for me and the cubs slow end performance is what really sells it for me.

Talking about going slow ,any thought on the highlanders pop out slats, I'd love to look at something like that on my Skywolf ?

 

Matty

 

 

[Dafydd Llewellyn]

Now you're cooking on gas ... well, pretty close to what I'm thinking about anyway.What's a blue-bush landing gear?

One capable of landing in saltbush. Ever driven across the Hay plains?

What about a one-piece steel spring-leg with sufficient track that it has a respectable travel? i.e. not one of the minimum-weight style a la Tecnam, but a real one?

 

 

[SDQDI]

Hmm sounds to me like you are talking about my plane fellas not that I'm conceited at all:wink: I agree wholeheartedly with hitc.

 

My main uses of my aircraft after local sticky beaking was intended to visit the inlaws and help out with mustering checking dams etc (not happening until I get a few more hours then do my ll endorsement) and I needed something which would handle an accidental gilgai (not sure how that's meant to be spelt) discovery. I have heard negative things about the trailing link but as far as I've seen it has worked perfectly.

 

I run the 26 inch bush wheels and others I've talked to have done plenty of time on them without hassles. Originally had the 8.50 x 6 but they don't ride anywhere near as nice over freshly ploughed dirt and I had a puncture before they had even seen a paddock.

 

With the travel of suspension combined with the big wheels you can't feel six inch ruts or lumps unless you are taxiing.

 

Anyway I'm not biased but so far I couldn't be happier with the hornet and would recommend them to anyone (obviously)

 

Operating costs work out to about 40$ per hour including maintenance and fuel costs

 

 

[SDQDI]

Ps saltbush is bad but lignum is worse on tyres, we (wife and I) spent four years west of Hillston and spending the day mustering in lignum always punctured a tyre or two.(bikes and vehicles not planes, if only I'd been flying back then)

 

 

[Head in the clouds]

One capable of landing in saltbush. Ever driven across the Hay plains?

Ah, I see, I thought you'd meant there was a type of gear called that. Yes, gear that could land on that kind of country is the type of thing, though not nearly essential, you can usually find a small claypan that's clear of most scrub. That kind of country is similar to the blacksoil grass clumps I mentioned. If you can land on those you're doing OK and big diameter wheels rather than tundra tyres are the go for that. When it's dry for extended periods the blacksoil turns to dust and blows away from around the roots of the grass leaving hard football-sized root clumps exposed. Mainly found in sheep country rather than cattle country though, typical of the Diamantina area between Longreach and Cloncurry. The sheep walk between the clumps and hasten the erosion. You'd only try and land on it in really serious circumstances. An old hand aeroplane musterer used to train others to muster sheep on that kind of country by telling the newbie to make sure he kept the flock tight together - "in case the engine stops, then you land on the mob, coz if you land on the clumps they'll rip your ass out ..."

 

What about a one-piece steel spring-leg with sufficient track that it has a respectable travel? i.e. not one of the minimum-weight style a la Tecnam, but a real one?

It's not just travel, it's also about not bouncing ... I have considered long spring gear with an inertia-reel style of take-up that acts like a shock absorber, taking up as the gear leg rises and only allowing it to rebound very slowly, perhaps using a viscous coupling unit or similar.

 

 

[Dafydd Llewellyn]

[quote=

 

Talking about going slow ,any thought on the highlanders pop out slats, I'd love to look at something like that on my Skywolf ?

 

Matty

 

Problem with slats is (a) They're another mechanism to wear & need maintenance; and they need to be linked together across the aircraft. (b) Slats, contrary to popular perception, increase the nose-down pitching moment - i.e. they add to the download on the tail. And © they do not do much for the takeoff roll, because you can't get sufficient angle of attack on them until after lift-off. I think there are preferable ways to approach the subject.

 

 

[Dafydd Llewellyn]

Ah, I see, I thought you'd meant there was a type of gear called that. Yes, gear that could land on that kind of country is the type of thing, though not nearly essential, you can usually find a small claypan that's clear of most scrub. That kind of country is similar to the blacksoil grass clumps I mentioned. If you can land on those you're doing OK and big diameter wheels rather than tundra tyres are the go for that. When it's dry for extended periods the blacksoil turns to dust and blows away from around the roots of the grass leaving hard football-sized root clumps exposed. Mainly found in sheep country rather than cattle country though, typical of the Diamantina area between Longreach and Cloncurry. The sheep walk between the clumps and hasten the erosion. You'd only try and land on it in really serious circumstances. An old hand aeroplane musterer used to train others to muster sheep on that kind of country by telling the newbie to make sure he kept the flock tight together - "in case the engine stops, then you land on the mob, coz if you land on the clumps they'll rip your ass out ..."

 

It's not just travel, it's also about not bouncing ... I have considered long spring gear with an inertia-reel style of take-up that acts like a shock absorber, taking up as the gear leg rises and only allowing it to rebound very slowly, perhaps using a viscous coupling unit or similar.

I meant, one should study the question of what a landing gear should be, to contend with that sort of surface. I suspect, some variant of wheel/ski gear, but it really needs some experiment to see what would work.

Damping a spring-leg is something we'd all like to discover how to do.

 

 

[metalman]

The issue I have is I can get off the ground in about 200 feet but need around 300-350 to land, it's good in that I know I'll always get out of anywhere I can get in but I would like to shorten the landings a bit

 

 

[Dafydd Llewellyn]

Is that from 50 feet, or is it just the ground roll? Because if it's the latter, it sounds unnecessarily long.

 

 

[Old Koreelah]

OK. Please let me know how you get on.

I fitted my new stall fences a couple of weeks ago, and have done one trip, but didn't have time to do stall tests until today.

I followed Dafydd's suggestions (http://www.recreationalflying.com/threads/do-vortex-generators-really-work.117300/page-2) but made my fences a little larger.

 

The biggest headache was doing major surgery to my carrier to accommodate the fences.

 

The results- power-off stalls, with first stage of flaps:

 

Without wing fence and stall strip: mushing at 41kt, losing 1000 fpm, then wing drop at 40kt.

 

With wing fences and stall strips: a disconcerting nodding and tailwagging at 45kt, losing 800fpm, no stall or wing drop. Presumably the oscillating is caused by the tail being bumped between the fence vortices. The nodding behaviour may be a result of the elevator rythmically bouncing off from the turbulent air from the inner wing.

 

Not the outcome I had hoped for; perhaps I can experiment with location of the stall strips

 

 

 

[eightyknots]

I would advise you very strongly NOT to use VGs over the full span; read what I said in post #21 on this thread.

 

Savannahs have full span VGs and seem by all accounts to have acceptable stall characteristics? Mine has had VGs added on the elevator.

I took this picture of a Savannah S being assembled at Archerfield Aerodrome 18 months ago. You can see that the VGs are full-span.

 

ICP also fits full-span vortex generator s to the XL and VG models. I understand that more than a thousand vortex generator equipped Savannahs are currently flying and, so far, I have not heard that the full-span arrangement has given any handling problems.

 

Dafydd, why do you advise against full-span VGs?

 

 

 

[Dafydd Llewellyn]

I fitted my new stall fences a couple of weeks ago, and have done one trip, but didn't have time to do stall tests until today.I followed Dafydd's suggestions (http://www.recreationalflying.com/threads/do-vortex-generators-really-work.117300/page-2) but made my fences a little larger.

The biggest headache was doing major surgery to my carrier to accommodate the fences.

 

The results- power-off stalls, with first stage of flaps:

 

Without wing fence and stall strip: mushing at 41kt, losing 1000 fpm, then wing drop at 40kt.

 

With wing fences and stall strips: a disconcerting nodding and tailwagging at 45kt, losing 800fpm, no stall or wing drop. Presumably the oscillating is caused by the tail being bumped between the fence vortices. The nodding behaviour may be a result of the elevator rythmically bouncing off from the turbulent air from the inner wing.

 

Not the outcome I had hoped for; perhaps I can experiment with location of the stall strips

You may be getting a kind of "falling leaf" effect, in which first one wing root separates and then the other - and it sets up a rythmic oscillation. I did warn that this might happen with a low-wing machine; with high wings, the initial stall spreads instantly from one wing fence to the other, so the whole centre-section stalls symmetrically, and there is no "tailwagging" effect.

You may or may not be able to improve matters by adjusting the stall strips.

 

I took this picture of a Savannah S being assembled at Archerfield Aerodrome 18 months ago. You can see that the VGs are full-span.ICP also fits full-span vortex generator s to the XL and VG models. I understand that more than a thousand vortex generator equipped Savannahs are currently flying and, so far, I have not heard that the full-span arrangement has given any handling problems.

 

Dafydd, why do you advise against full-span VGs?

 

[ATTACH=full]30838[/ATTACH]

That can only mean, there is insufficient elevator authority to stall the wing, in the presence of the VGs. However, the elevator authority increases as the CG moves aft; do you have any idea where these aeroplanes are, in the allowable CG range? If there is sufficient elevator authority to stall any part of the wing, within the aircraft's permissible CG range, the stall is likely to be extremely vicious.

 

 

[eightyknots]

That can only mean, there is insufficient elevator authority to stall the wing, in the presence of the VGs. However, the elevator authority increases as the CG moves aft; do you have any idea where these aeroplanes are, in the allowable CG range? If there is sufficient elevator authority to stall any part of the wing, within the aircraft's permissible CG range, the stall is likely to be extremely vicious.

I am not sure, Dafydd. Perhaps owners of VG, XL or S model Savannahs would care to comment??

 

 

[AVOCET]

Thanks, Tom. I'd use VGs on my own aircraft - but set up for the improved stall behaviour, not because of the numbers. What they do, is to make the full speed range usable. One of the demonstrations I have used in the Seeker, is to simulate a violent evasive manoeuvre - such as one might make if somebody were shooting at you - from 65 knots (the flaps-up stall speed being 56 knots): Boot full rudder, full aileron, stick on back stop and full power, to haul the thing into a tight turn. Any normal aeroplane would flick-roll from such treatment. The Seeker simply turns and keeps flying, with a barely-perceptible buffet from the stalled centre-section. The people marketing VGs are pushing the wrong aspect of them, in my view; used properly, they are a magnificent safety device. Used wrongly, they are bloody dangerous. I just wanted to explain that to people.

what I would give to have dafydd living close by

mike